#include "widget.h"
#include "ui_widget.h"


void Widget::init()
{
    ui->treeWidget->clear();

    QTreeWidgetItem *group1 = new QTreeWidgetItem(ui->treeWidget);

    group1->setText(0,"group1");
    group1->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable);
    group1->setCheckState(0,Qt::Unchecked);

    QTreeWidgetItem *subItem11 = new QTreeWidgetItem(group1);
    subItem11->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable);
    subItem11->setText(0,"subItem11");
    subItem11->setCheckState(0,Qt::Unchecked);

    QTreeWidgetItem *subItem12 = new QTreeWidgetItem(group1);
    subItem12->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable);
    subItem12->setText(0,"subItem12");
    subItem12->setCheckState(0,Qt::Unchecked);

    QTreeWidgetItem *subItem13 = new QTreeWidgetItem(group1);
    subItem13->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable);
    subItem13->setText(0,"subItem13");
    subItem13->setCheckState(0,Qt::Unchecked);

    QTreeWidgetItem *subItem14 = new QTreeWidgetItem(group1);
    subItem14->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable);
    subItem14->setText(0,"subItem14");
    subItem14->setCheckState(0,Qt::Unchecked);

    QTreeWidgetItem *group2 = new QTreeWidgetItem(ui->treeWidget);

    group2->setText(0,"group2");
    group2->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable);
    group2->setCheckState(0,Qt::Unchecked);

    QTreeWidgetItem *subItem21 = new QTreeWidgetItem(group2);
    subItem21->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable);
    subItem21->setText(0,"subItem21");
    subItem21->setCheckState(0,Qt::Unchecked);

    QTreeWidgetItem *subItem22 = new QTreeWidgetItem(group2);
    subItem22->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable);
    subItem22->setText(0,"subItem22");
    subItem22->setCheckState(0,Qt::Unchecked);

    QTreeWidgetItem *subItem23 = new QTreeWidgetItem(group2);
    subItem23->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable);
    subItem23->setText(0,"subItem23");
    subItem23->setCheckState(0,Qt::Unchecked);
}

void Widget::updateParentItem(QTreeWidgetItem *item)
{
    QTreeWidgetItem *parent = item->parent();

    if(parent == NULL)
    {
        return;
    }

    int selectedCount = 0;
    int childCount = parent->childCount();
    for(int i = 0; i < childCount; i++)
    {
        QTreeWidgetItem *childItem = parent->child(i);
        if(childItem->checkState(0) == Qt::Checked)
        {
            selectedCount++;
        }
    }

    if(selectedCount <= 0)
    {
        parent->setCheckState(0,Qt::Unchecked);
    }
    else if(selectedCount > 0 && selectedCount < childCount)
    {
        parent->setCheckState(0, Qt::PartiallyChecked);
    }
    else if(selectedCount == childCount)
    {
        parent->setCheckState(0,Qt::Checked);
    }
}

void Widget::treeItemChanged(QTreeWidgetItem *item, int column)
{
    QString itemText = item->text(0);

    if(Qt::Checked == item->checkState(0))
    {
        QTreeWidgetItem* parent = item->parent();
        int count = item->childCount();
        if(count > 0)
        {
            for(int i = 0; i < count; i++)
            {
                item->child(i)->setCheckState(0, Qt::Checked);
            }
        }
        else
        {
            updateParentItem(item);
        }
    }
    else if(Qt::Unchecked == item->checkState(0))
    {
        int count = item->childCount();
        if(count > 0)
        {
            for(int i = 0; i < count; i++)
            {
                item->child(i)->setCheckState(0, Qt::Unchecked);
            }
        }
        else
        {
            updateParentItem(item);
        }
    }
}

Widget::Widget(QWidget *parent) :
    QWidget(parent),
    ui(new Ui::Widget)
{
    init();
    connect(ui->treeWidget,SIGNAL(itemChanged(QTreeWidgetItem *,int)),this,SLOT(treeItemChanged(QTreeWidgetItem *,int)));

    ui->setupUi(this);
}

Widget::~Widget()
{
    delete ui;
}
